Selective call systems of today are utilized to transmit messages to voice or data communication receivers, i.e., pagers, carried by people who may not always be accessible by telephone. Some selective call systems, commonly known as wide area paging services, transmit messages to subscribers within a large geographic area. Wide area paging services meet the needs of subscribers, such as sales or service people, who are constantly traveling within a large area. Other selective call systems, called local area or on-site paging services, transmit messages within a localized area. This type of paging service is designed to transmit messages to people who are frequently away from their desks but seldom leave their campus, e.g., the factory, office, hospital, etc., in which they work. Each paging service, whether wide area or on-site, is assigned a unique frequency, i.e., channel, in a manner such that systems proximally located to each other will operate on distinct channels, thereby preventing interference between different paging services.
With the proliferation of selective call messaging, many users subscribe to more than one paging service. For example, a user who travels frequently may subscribe to a wide area paging service to receive messages while traveling and subscribe to an on-site paging service to receive messages while on campus. Doctors, for instance, may need the services of a wide area paging service while on call and may need the services of an on-site paging service while at work in the hospital. A subscriber to more than one paging service, however, must have a pager for each paging service to which he subscribes. Therefore, a subscriber of more than one paging service must typically purchase or rent multiple pagers, which are often very expensive. Furthermore, if the subscriber wishes to receive messages on more than one paging service at the same time, he must carry a pager for each of the paging services in which he desires to receive messages. In such a situation, the subscriber is faced with the problem of how to wear a number of often bulky and unattractive pagers while maintaining a dignified appearance. Furthermore, if the paging services do not have overlapping coverage areas, the subscriber will not be able to receive messages broadcast by the paging services at the same time even if he carries a pager for each paging service. In this case, he can only receive messages from each paging service while he is located within the coverage area of the paging service. Therefore, the subscriber may often not receive messages broadcast by a first paging service while he is in the coverage area of a second paging service. For example, a sales person who constantly travels between two different cities may subscribe to two paging services, each providing coverage for one of the two cities. He will, however, only receive messages broadcast by each of the paging services while he is within the coverage area of each paging service. As a result, while he is in the first city, the sales person will miss messages broadcast by the paging service covering the second city.
Thus, what is needed is a method by which a subscriber of multiple paging services having unique coverage areas may automatically receive messages broadcast by each of the multiple paging services at all times. Furthermore, the subscriber should be able to receive the messages broadcast by each of the multiple paging services on a single pager.